It takes 3 employees, who all work at the same rate, 5 hours to comple

We are given that 3 employees, who all work at the same rate, can type 500 pages in 5 hours.

So, the rate of the 3 employees is 500/5 = 100 pages per hour. Let’s use a proportion to determine x, the rate of the 6 employees.

3/100 = 6/x

3x = 600

x = 200

Since time = work/rate, it takes 6 workers 750/200 = 3.75 hours to complete 750 pages.

Answer: C

3 employees => 5 hrs => 500 pages
6 employees => 2.5 hrs => 500 pages
6 employees => ? hrs => 750 pages

work = rate x time
500 = r x 2.5
r = 200

work = rate x time
750 = 200 x t
t = 3.75

Which is answer C

Hi All,

We're told that it takes 3 employees, who all work at the same rate, 5 hours to complete the typing of a 500 page document. We're asked how long it would take 6 similar employees to complete a document that is 750 pages. The answer choices are 'spread out enough' that you can actually answer this question without doing too much math - you just need a little logic and a couple of 'comparisons.'

IF.... we were just doubling the number of employees, then the original job would take HALF of the time (2.5 hours instead of the original 5 hours). We're not doing the original job though - we're doing MORE work - so the time needed has to be GREATER than 2.5 hours.

Since we're doubling the number of employees, but we're NOT doubling the number of pages (that number is only increased by 50%), we know that the total amount of time would have to be LESS than 5 hours.

There's only one answer that falls in that range....

Final Answer:

GMAT assassins aren't born, they're made,
Rich

(# of workers) * (rate) * (time) = Work

(Simply add one extra column, number of workers, to standard RTW table. Manipulate it the same way as RT = W.)

Individual worker rate, r?

(# of workers) * (rate) * (time) = Work\(^{1}\)

(3) * (r?) * (5) = 500

r = \(\frac{500}{(3*5)}=\frac{500}{15}=\frac{100}{3}\)

Use that rate to find time in the second scenario: At that rate, how much time will it take 6 workers to type 750 pages?

(# of workers) * (rate) * (time) = Work\(^{2}\)

6 * \((\frac{100}{3}\)) * (t?) = 750

t = \(\frac{750}{(\frac{600}{3})}=\frac{750}{200}=\frac{15}{4}=3.75 hrs\)

Answer C

What follows is just manipulation of equation

\(^{1} r =\frac{W}{(No.Workers*t)}\)

\(^{2}t = \frac{W}{(No.Workers * r)}\)

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